Australians are bracing themselves for further bush fires, as forecasters warn of searing temperatures and high winds on Wednesday.

But with thousands of firefighters worked to shore up defences in the vulnerable south-east region, one of their colleagues appeared in a Melbourne court charged with arson.

Conditions will be a lot worse tomorrow and very difficult on Thursday

John Winter, New South Wales Fire Service

John Christopher Andersen, 18, a volunteer firefighter
from Victoria state, was arrested close to a fire on Monday and is charged with lighting 12 fires over the past six weeks in a
forest north of Melbourne.

While much of Australia is battling the fires, parts of the north-east are suffering from flooding.

The isolated community of Burketown in Queensland's Gulf of Carpentaria has been cut off for three weeks, and supplies were airlifted to the area on Tuesday.

Local council chief executive Craig Turnour said the town - much of which is built on stilts - had been caught unprepared by the flooding.

"There's no fresh milk, fruit or vegetables, bread is very limited, so it's just a matter of stocking up on those things until the roads open again," he said.

Brief respite

Many people in south-east Australia had a brief respite from the fires on Monday, as light rain and cooler temperatures brought relief to both firefighters and residents.

More than 1,000 evacuees returned to their homes, although resort towns such as Cooma and Jindabyne remained under threat.

Firefighters took advantage of the milder conditions, with 4,000 people engaged in a process known as back burning - creating firebreaks by deliberately scorching the earth with small fires to prevent the ground from burning again.

"We have a window of 24 hours to get things done," New South Wales state Rural Fire Service spokesman John Winter said on Tuesday. "Conditions will be a lot worse tomorrow and very difficult on Thursday."

So far emergency teams have prevented a repeat of last weekend's disaster near the federal capital, Canberra - where four people were killed and 530 homes went up in flames.

But the authorities warned that after a month of wild fires in the region, many blazes were still out of control.

Some 80 blazes continue to burn across New South Wales, including one in the Royal National Park bordering the south-eastern suburbs of Australia's largest city, Sydney.

The fires have been fed by bone-dry conditions, following 10 months of El Nino-aggravated drought.